Method of converting oils in vapor phase



June 23, 1931. c. R. WAGNER METHOD OF CONVERTING OILS IN VAPOR PHASE Filed Aug. 2l. 1928 n. Le MIU l.-

Patented June 23, 1931 UNITED STATES PATENT 'o1-Fics CARY R. WAGNER, 0F CHICAGO, ILLINOIS, ASSIGNOR TO GYRO PROCESS COMPANY, 0F DETROIT, MICHIGAN, A CORPORATION 0F MICHIGAN METHOD OF CONVERTING OILS IN VAPOR IPHASE Application led August 21, 1928. Serial No. 300,998.

This invention relates to an improved method and apparatus for effecting the cracking of petroleum oils wherein such 'oils undergo molecular decomposition while they are maintained in a state of vapor, and the invention has particular` application to the so called high temperature systems of oil eonversion which are utilized in the production of motor fuels or oils having a high antidetonating value.

It is a primary object of the invention to provide 1n a system of this character a method of operation and accompanying apparatus so correlated as to secure maximum conversion of the oil vapors with minimum temperature fluctuation in such vapors during their passage through the conversion zone or elements of the system after a desired conversion temperature has been obtained.

It is also another object of the inven tion to provide for maximum conversions for each throu h-put of oil vapor through the converter w1th the use of relatively low temperatures and also to avoid employing relatively high temperature ranges, where the rate of reaction 1s so rapid that it is hard to control the system and where permanent gas is formed at a high rate.

For a further understanding of the invention reference is to be had to the following description and the accompanying drawings wherein Figure l'representsa vertical sectional vieW taken through an oil converter formed in accordance with the present -inven tion and Figure 2 represents a flow diagram showing the converter arranged with accessory apparatus.

Referring more particularly to the accompanying drawings, the numeral 1 designates an oil heater or converter of a type employed inconnection with vapor phase methods of oil conversion. The heater is formed to include, in this instance, the'eustomary walls or setting 2 in which is positioned a bank of converting tubes or elements 3. The interior of the converter may be heated by a fuel burner 4 so that appropriate operating temperatures may prevail in the converter. Oil vapor, obtained from any suitable source such as the vaporizer andv evaporator shown 1n A /through the varlous tubes of Figure 2, enters the first pass of the vconverter tubes by way ofthe inlet line 5 at a temperature, for example, of 670 F., and these ineon'iing vapors, while flowing through the first pass of the converter tubes, are subjected to the elevated temperatures of the converter so that the vapors quickly reach a conversion temperature in excess of 1000" F. In fact, when the vapors leave the first pass their tcu'iperatures approximate 1050o F.

I then pass the vapors through an elongated soaking orl reaction chamber which in this instance is provided in the form of an elongated return bend 6', the internal area of which may be regulated to control the velocity of flow of the oil vapor therethrough either at equivalent or varying velocities with respect to the rate of-flow of the vapors the converter proper.

It is preferable to place a core of catalytic material such as ferrous oxide in one or more,

of the tubes 3 of the converter, the return bends, however, are preferably empty and devoid of Contact. or catalytic materials. From the return .bends 6 the vapors travel through the second pass la of the converter and are again subjected/to the heat of the converter, and from the pass 3a the vapors travel into a second elongated return bend Ga, disposed, like the bend 6. exteriorly of the setting and removed from direct. exposure to the high internal temperatures of the converter. Fro'm the return bend 6a the vapors travel through the third pass 3b ofV the converter and thence through a third return bend GZ), arranged exteriorly of the converter walls and immediately below the return bend 6. the vapors travel through the fourth pass 30 of the converter in which they receive their linal heat and are discharged from the converted by way of the line 7 for separation and fractionation in any desirable manner0 such as, for example, by passing the saine thru the fractionating tower and into the cracked oil tank. shown in Figure 2. It will be appreciated thatthe invention is not limited to the number of converter passes or return bends set forth, since the description From the return bend 6b above given is merely one of explanation rather than one of limitation. The pass 3a may or may not be provided with a catalytic core, while preferably the tubes comprising the passes 25?: and 3c are empty or devoid of catalyticmaterials.; y ,p l

Dtrringtheitravel of the vapors through the tube or tubes ot the lirst pass 3 the tempera.- ture of the vapors reaches approximately 10.70 F'. and th'e'reti'irn bend (i is just; large enough to permit endothermic reactions to go far enough to drop the temperature 20 to F. in 'usually oneto three seconds time.

1 `orexainple,the vapors enter the return hendat. a temperature of 1050 F. and leave the return bendat a temperature of 1020 F. During the travel of the vapors through the tube or tubes of thc pass 3a. their temperature is -iagain raised from, for example, 1020" F. to

1050D or 1100o F., at which temperatures thevapors enter the .second return bend or bends indicated at 6a. .The return bends are preferably protected by heat insulation cov- Vering to reduce heat losses through radiation.

After passing thronghfthe return bend 0a the vapors enter the pass 3b at a temperature varying between 1000o and 1025o F. and enter the third return bend t at a temperature varying between 1050o and 1100o F.

The vapors leaving the Areturn bend 6b possess a temperature approximately of from between 1000o and-1025Q F., and after traversing the fourth bank of converter tubes 3G the vapors are discharged from the converter into a suitable cooling apparatus at. a tcmperature., for example, ot'lth'itlo to 1100 l".

This construction or method of operation provides alternate heating and soaking7 of the oil vapors so as to secure l'naxinuun conversion with minimum tcnil-icrature fluctuation or. in other words, to provide for an increased production of a motor fuel distillate t'or each through-put of material traversingr the,l converter. 'l`he vprocess is also carried out. b v the construction .set forth, in such manner as to avoid going into very high tcmpcrature ranges, where the rate ot reaction is so rapid that it is tlillicult to control. and where permanent gas is t'cnaned at a high rate. 1n vapor phase -svstems it is desirable to secure the highest'y per cent ot' motor fuel productV obtaiuabh` willi the least kamount ot' permanent' gas and also to obtain the highest rate of conversion for cach through-put otl material through thc converti r. lt is to the obtaining ofl these ends that the |iresent invention is chietly directed. l'leretol'ore it has been ciistoniary to employ the shortest pos- Y through `4uch tube banks is progressivi-lv increased troni the inlet to the outlet end of the con.'ertcr. 1 have found that by employverter tubes is practically-the same as the temperature of the vapors leaving the outlet end of the tubes 3c. The tube banks are so arranged that. it usuallyv required from four to ten .seconds for a given body of vapor to traverse, the full length of the converter junit. rl`his method of :ilternatingly heating the vapors and-then providingr the intermittent stinking chambers results in higher conversit'inonl a single through-put, which decreases fuel cost;`- and increases the capacity of the apparatus without increasing the gas to gasoline ratio.

lfhatis claimed is:

1. The process ol cracking liight-boiling pointhvdrocarlions in the vapor phase which comprises vaporizing the hydrocarbons. separating the vapors from the unvaporized hydrocarbons` heatingl the vapors in a stream to a cracking temperature. passing the vapors .thru a zone wherein substantially only endotherniic cooling occurs. again heating the vapors to a cracking teinlierature. and condenslngand collecting the products.

2. The process of cracking high .boiling point hydrocarbons in the vapor phase which comprises vaporizing the hydrocarbons, Separating the vapors from the unvaporizcd hydrocarbons. heating the vapors in a stream to a cracking temperature in the presence of a catalyst. passing the vapors thru a zone wherein substantially only endothermic cooling occurs. again heating the vapors to a cracking temperature. `and condensing and collecting the products.

3. The process of cracking high boiling point hydrocarbons in the vapor phase which comprises vaporizing the hydrocarbons, separating' the vapors from the nnvaporized hydrocarbons. heating the-vapors in va stream to av cracking temperature above 1000 F., passing the vapors thru a zone wherein substantially only endothermic cooling occurs to reduce the vapors to a temperature of not lower than 1000" F..`again heating the vapors to a cracking temperature, and condensing and collecting the Iirodncts. A

el. 'l`he process of cracking high boiling point, lrvdrocarbons in the vapor phase which comprises vaporizing the, hydrocarbons. sep-.

arat ingr the vapors fronrthc unvaporized hydroearhons. heating tht` vapors in a stream to a cracking temperature, passing the vapors thru a zone wherein sul'istantially only endotherniic cooling occurs without. substantial concurrent l'ormzfition of condensate, again heating tbe vapors to a cracking temperature. and condensing and collecting the products.

5. The process of cracking high boiling point hydrocarbons in the vapor phase which comprises vaporizing the hydrocarbons, separating the vapors from the unvaporized hydrocarbons, heating the vapors in a stream to a cracking temperature, passing the vapors thru a zone wherein substantially only endothermic cooling occurs to a point above a critical temperature below which endothermic reactions cease, again heating the vapors to a cracking temperature, and condensing and collecting the products.

6. The process of cracking high boiling point hydrocarbons in the vapor phase which comprises vaporizing the hydrocarbons, separating the vapors from the unvaporized hydrocarbons, heating the vapors in a stream to a cracking temperature from 1000o F. to 1l00 F., passing the vapors thru a Zone wherein substantially only endothermic cooling occurs to reduce the vapors to a temperature of not lower than 1000o F. and without substantial interruption of the endothermic reactions taking place therein, again heating the vapors to a cracking temperature, and condensing and collecting the products.

In testimony whereof l aflix my signature.

CARY R. WAGNER. 

